Retroreflective conspicuity marking systems are used widely in traffic control systems and personal safety systems to increase the visibility of objects in poor lighting conditions such as, for example, night lighting conditions or conditions of inclement weather. Common examples include retroreflective sheeting for highway signing applications, construction work zone markers such as traffic cones, and retroreflective pavement marking systems.
Such retroreflective conspicuity marking systems may be considered passive systems in that they serve only to retroreflect light incident on the object from an external light source. In some applications it may be desirable to provide an active conspicuity marking system which illuminates an object to increase its conspicuity in typical daylight conditions and which also provides retroreflective conspicuity marking.
Commonly assigned, co-pending patent application U.S. Ser. No. 08/518,337 discloses and claims a light distribution system which comprises a light guide and at least one light extraction overlay optically coupled with the light guide for extracting light from the light guide.